TY - JOUR
T1 - Estrogen Receptor-mediated Activation of the Serum Response Element in MCF-7 Cells through MAPK-dependent Phosphorylation of Elk-1
AU - Duan, Renqin
AU - Xie, Wen
AU - Burghardt, Robert C.
AU - Safe, Stephen
PY - 2001/4/13
Y1 - 2001/4/13
N2 - 17β-Estradiol (E2) induces c-fos protooncogene expression in MCF-7 human breast cancer cells, and deletion analysis of the c-fos promoter showed that the serum response element (SRE) at -325 to -296 was E2-responsive. The mechanism of ligand-activated estrogen receptor α (ERα)-dependent activation of gene expression through the SRE was determined by mutational analysis of the promoter, analysis of mitogen-activated protein kinase (MAPK) pathway activation by E2, and transforming growth factor α (TGF-α) as a positive control. In addition, ERα-negative MDA-MB-231 breast cancer and Chinese hamster ovary cells were used as reference cell lines. The results showed that transcriptional activation of the SRE by E2 was due to ERα activation of the MAPK pathway and increased binding of the serum response factor and Elk-1 to the SRE. Subsequent studies with dominant negative Elk-1, wild type, and variant GAL4-EIk-1 fusion proteins confirmed that phosphorylation of Elk-1 at serines 383 and 389 in the C-terminal region of Elk-1 is an important downstream target associated with activation of an SRE by E2. Both E2 (ERα-dependent) and growth factors (ERα-independent) activated the SRE in breast cancer cells via the Ras/MAPK pathway; however, in ER-negative CHO cells that do not express a receptor for TGF-α, only hormone-induced activation was observed in cells transfected with ERα.
AB - 17β-Estradiol (E2) induces c-fos protooncogene expression in MCF-7 human breast cancer cells, and deletion analysis of the c-fos promoter showed that the serum response element (SRE) at -325 to -296 was E2-responsive. The mechanism of ligand-activated estrogen receptor α (ERα)-dependent activation of gene expression through the SRE was determined by mutational analysis of the promoter, analysis of mitogen-activated protein kinase (MAPK) pathway activation by E2, and transforming growth factor α (TGF-α) as a positive control. In addition, ERα-negative MDA-MB-231 breast cancer and Chinese hamster ovary cells were used as reference cell lines. The results showed that transcriptional activation of the SRE by E2 was due to ERα activation of the MAPK pathway and increased binding of the serum response factor and Elk-1 to the SRE. Subsequent studies with dominant negative Elk-1, wild type, and variant GAL4-EIk-1 fusion proteins confirmed that phosphorylation of Elk-1 at serines 383 and 389 in the C-terminal region of Elk-1 is an important downstream target associated with activation of an SRE by E2. Both E2 (ERα-dependent) and growth factors (ERα-independent) activated the SRE in breast cancer cells via the Ras/MAPK pathway; however, in ER-negative CHO cells that do not express a receptor for TGF-α, only hormone-induced activation was observed in cells transfected with ERα.
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U2 - 10.1074/jbc.M005492200
DO - 10.1074/jbc.M005492200
M3 - Article
C2 - 11145955
AN - SCOPUS:0035853819
SN - 0021-9258
VL - 276
SP - 11590
EP - 11598
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 15
ER -